1. Field of the Invention
The present invention relates to an electronic endoscope system, and more particularly, to an electronic endoscope system in which an optical adaptor having illuminating means is attached to the distal end of an insertion unit.
2. Description of the Related Art
Recently, an endoscope system has widely been used. The endoscope system observes the organ in the body cavity by inserting an elongated insertion unit into the body cavity, and performs various treatments by using a treatment tool inserted in a treatment tool channel if necessary. Further, in the industrial field, the endoscope device observes and inspects the inner scratch or corrosion of a boiler, turbine, engine, and chemical plant.
In the above-mentioned endoscope system, since a dark portion, such as the body cavity, is often observed and the brightness in the observation therefore needs to be ensured. Then, an electronic endoscope system is widely used in which a light-emitting device, such as a lamp or an LED, is arranged, as illuminating means, at the distal portion of the insertion unit, and a subject is observed by an image pickup device, such as a CCD while illuminating the subject by the illuminating means.
Recently, the observed portion is complicated and is varied in accordance with the development of the endoscope medical field. The medical stuff requires an electronic endoscope system having illuminating means corresponding to the observed portion and an image pickup device with the pixel array (e.g., difference in pixel size or NTSC or PAL). Therefore, the diameter dimension of a pipe, serving as an observed target, is varied, e.g., large to small in the industrial electronic endoscope system and various optical adaptors corresponding to the diameter dimension or inspection target are prepared for various inspections.
Conventionally, a system using an interchangeable optical adaptor including an LED is proposed, as an electronic endoscope system having an interchangeable optical adaptor. For example, the electronic endoscope system has an interchangeable adaptor in which a plurality of LEDs, serving as illuminating means, are arranged near an objective lens, and further has a mechanism for supplying the power to the LED in the main body of the electronic endoscope. The contact on the proximal end of the interchangeable optical adaptor is connected to the contact of the distal end of the endoscope insertion unit, thereby driving the LEDs included in the interchangeable optical adaptor (refer to, e.g., Japanese Unexamined Patent Application Publication No. 10-216085 and Japanese Unexamined Patent Application Publication No. 2000-89130).
Further, the electronic endoscope system comprises an interchangeable optical adaptor having a plurality of LEDS, serving as illuminating means and a CMOS image sensor, serving as an image pickup device, and further an operating unit having a circuit for supplying the power to the LEDs and the CMOS image sensor. A connecting unit arranged to the proximal end of the interchangeable optical adaptor is connected to a connecting unit arranged to the distal end of an endoscope insertion unit, thereby driving the LEDs included in the interchangeable optical adaptor (refer to, e.g., Japanese Unexamined Patent Application Publication No. 2001-61777).